Gravity Forms Cookies // Saves the query string parameters from a users visit to a cookie and allows these values to be populated via Gravity Forms' Dynamic

gistfile1.php

<?php
/**
Plugin Name: Gravity Forms Cookies
Plugin URI: http://ounceoftalent.com/
Description: Saves the query string parameters from a users visit to a cookie and allows these values to be populated via Gravity Forms' Dynamic Population feature.
Version: 1.5
Author: David Smith
Author URI: http://ounceoftalent.com
License: GPL2
*/

class GFCookie {
    
    public static $cookie_prefix = 'gfc_';
    public static $session = false;
    public static $fresh_cookies = array();
    
    public static function init() {
        
        //GFCookie::delete_cookies(); exit;
        
        if(!is_admin()) {
            add_action('parse_request', array('GFCookie', 'save_cookie'), 9);
            add_action('gform_pre_render', array('GFCookie', 'load_cookie'));
        }
        
        add_shortcode('gf_cookied_link', array('GFCookie', 'cookied_link_shortcode'));
        
    }
    
    public static function save_cookie() {
        
        // if cookies are not enabled, default to session use
        // start the session regardless of $_GET being empty as session may have been previously populated
        if(!self::cookies_enabled()) {
            session_start();
        }
        
        // don't do anything with cookie if there is no data
        if(!empty($_GET))
            self::save_get_data();
        
        self::save_server_data();
        
    }
    
    public static function load_cookie($form = null) {
        
        $cookie = self::get_cookie_data(false);
        
        foreach($cookie as $key => $value) {
            
            // skip cookies that were not added by us
            if(strpos($key, self::$cookie_prefix) === false)
                continue;
            
            // load cookie value into $_GET for population into Gravity Forms
            $key = str_replace(self::$cookie_prefix, '', $key);
            $_GET[$key] = $value;
            
        }
        
        // if gfc referrer is set, find {referer} merge tag and replace
        if(self::get_cookie_data('HTTP_REFERER')) {
            foreach($form['fields'] as &$field) {
                if(strpos(rgar($field, 'defaultValue'), '{referer}') !== false)
                    $field['defaultValue'] = str_replace('{referer}', self::get_cookie_data('HTTP_REFERER'), $field['defaultValue']);
            }
        }
        
        return $form;
    }
    
    public static function get_cookie_data($key = false) {
        
        $session = isset($_SESSION) && is_array($_SESSION) ? $_SESSION : array();
        $cookie = self::cookies_enabled() ? $_COOKIE : $session;
        
        // cookies that have not yet been sent through the header are merged with existing cookies
        $cookie = array_merge($cookie, self::$fresh_cookies);
        
        if($key === false)
            return $cookie;
        
        $gfc_key = self::$cookie_prefix . $key;
        
        return rgar($cookie, $gfc_key);
    }
    
    public static function save_get_data() {
        
        $reserved_words = array('attachment_id', 'author', 'author_name', 'calendar', 'cat', 'category', 'category__and', 'category__in', 'category__not_in', 'category_name', 'comments_per_page', 'comments_popup', 'cpage', 'day', 'debug', 'error', 'exact', 'feed', 'hour', 'link_category', 'm', 'minute', 'monthnum', 'more', 'name', 'nav_menu', 'nopaging', 'offset', 'order', 'orderby', 'p', 'page', 'page_id', 'paged', 'pagename', 'pb', 'perm', 'post', 'post__in', 'post__not_in', 'post_format', 'post_mime_type', 'post_status', 'post_tag', 'post_type', 'posts', 'posts_per_archive_page', 'posts_per_page', 'preview', 'robots', 's', 'search', 'second', 'sentence', 'showposts', 'static', 'subpost', 'subpost_id', 'tag', 'tag__and', 'tag__in', 'tag__not_in', 'tag_id', 'tag_slug__and', 'tag_slug__in', 'taxonomy', 'tb', 'term', 'type', 'w', 'withcomments', 'withoutcomments', 'year', 'DBGSESSID');
        
        foreach($_GET as $key => $value) {
            if(!in_array($key, $reserved_words)) {
                self::save_data($key, $value);
            }
        }
        
    }
    
    public static function save_server_data() {
        
        $server_keys = array('HTTP_REFERER');
        
        foreach($_SERVER as $key => $value) { 
            if(in_array($key, $server_keys))
                self::save_data($key, $value);
        }
        
    }
    
    public static function save_data($key, $value) {
        
        $gfc_key = self::$cookie_prefix . $key;
        
        if(self::cookies_enabled()) {
            if(!rgar($_COOKIE, $gfc_key)) {
                setcookie($gfc_key, $value, time() + 60*60*24*60, '/');
                self::$fresh_cookies[$gfc_key] = $value;
            }
        } else {
            if(!rgar($_SESSION, $gfc_key)) {
                $_SESSION[$gfc_key] = $value;
                self::$fresh_cookies[$gfc_key] = $value;
            }
        }
        
    }
    
    /**
    * WP uses cookies by default so if $_COOKIES global is empty, cookies are likely not enabled
    * 
    */
    public static function cookies_enabled() {
        return !empty($_COOKIE);
    }
    
    public static function delete_cookies() {
        foreach($_COOKIE as $key => $value) {
            if(strpos($key, self::$cookie_prefix) !== false) {
                self::delete_cookie($key);
            }
        }
    }
    
    public static function delete_cookie($key) {
        setcookie($key, null, time() - 3600, '/');
    }
    
    public static function cookied_link_shortcode($atts) {
        
        extract( shortcode_atts( array(
            'url' => false
        ), $atts ) );
        
        return !$url ? '' : gf_get_cookied_link($url);
    }
       
}

GFCookie::init();

if(!function_exists('gf_get_cookied_link')) {
function gf_get_cookied_link($url) {
        
    $cookies = GFCookie::get_cookie_data();
    $gfc_cookies = array();
    
    foreach($cookies as $key => $value) {
        if(strpos($key, GFCookie::$cookie_prefix) !== false) {
            $key = str_replace('gfc_', '', $key);
            $gfc_cookies[$key] = str_replace(array('http://', 'https://'), '', $value);
        }
    }
    
    return add_query_arg($gfc_cookies, $url);
}
}

@Cometeelcoco Glad to hear it! What'd you use it for?

Hi David. Can you tell me how to use this code?

@michaelcomceptum What are you trying to do? That might be a better place to start.

@Cometeelcoco Glad to hear it! What'd you use it for?

For Public relations people who refer people to my page and it was necessary that with a referral link a cookie would remain on the pc in case they later decided to make the purchase. Thank you very much for this great code. It also continues to work in Gravity Forms 2.5 in case anyone doubted it. A big hug.

@Cometeelcoco Fantastic!

What type of cache exclusion do you recommend for implementing this on a wpengine hosted website? This seems to only work when you're logged during my testing.

@adonnan Does WP Engine support exempting any cookie with a prefix? If so, exempting any cookie with the "gfc_" prefix should do the trick.

@spivurno That did the trick, thanks! I've been trying to figure that one out for a while.

Glad to help, @adonnan!

@maan1234, I'm seeing the same issue with first time visitors. Your solution of returning true from cookies_enabled seems to fix the issue. Would this change introduce any new potential issues with how this is currently implemented?

@spivurno, thanks for the great snippet!

@taylor-onfido My pleasure!

Wow David, 10 years ago and still found useful your creations, like this one. One thing: how can implement a way to update the cookies created by query string when a new query string is created? I saw the part //GFCookie::delete_cookies(); exit; at beginning but how to use this function to clear the cokies created? Kind regards

@amar8105alva Glad you're still finding this useful!

You can call GFCookie::delete_cookies() anytime before content is being rendered to the screen to delete all cookies created by GFCookie. For example, you could do something like:

add_action( 'init', function() {
    GFCookie::delete_cookies();
}, 9 );